iio: adc: ad7091r8: Fix error code in ad7091r8_gpio_setup()

There is a copy and paste error so it accidentally returns ->convst_gpio
instead of ->reset_gpio.  Fix it.

Fixes: 0b76ff4 ("iio: adc: Add support for AD7091R-8")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/fd905ad0-6413-489c-9a3b-90c0cdb35ec9@moroto.mountain
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Author: Dan Carpenter

drivers/iio/adc/ad7091r8.c

@@ -195,7 +195,7 @@ static int ad7091r8_gpio_setup(struct ad7091r_state *st)
 	st->reset_gpio = devm_gpiod_get_optional(st->dev, "reset",
 						 GPIOD_OUT_HIGH);
 	if (IS_ERR(st->reset_gpio))
-		return dev_err_probe(st->dev, PTR_ERR(st->convst_gpio),
+		return dev_err_probe(st->dev, PTR_ERR(st->reset_gpio),
 				     "Error on requesting reset GPIO\n");
 
 	if (st->reset_gpio) {